The present invention relates to a brake for an open-end spinning device and, more particularly, to a brake for an open-end spinning device having a rotor housing, a spinning rotor disposed in the rotor housing, and a support-disk bearing defining a bearing nip, wherein the spinning rotor is affixed to a shaft extending from the housing and rotatably supported in the bearing nip of the support-disk bearing for high speed rotation of the shaft and the rotor.
Open-end rotor spinning devices with brake devices which act on the rotor shaft of the spinning means are disclosed in numerous patent publications and have long been known in the state of the art.
For example, German Patent Publication DE 36 30 256 Al describes a brake for an OE spinning rotor which brake comprises a brake lever with a brake lining placeable from below against the rotor shaft in combination with two pressure pad devices with cheeks similar to brake linings which act from above on the rotor shaft to hold down the shaft during braking. The cheeks of the holding-down devices have a different coefficient of friction than the brake lining arranged on the brake lever.
Moreover, German Patent Publications DE 36 13 843 C2, DE 39 42 402 Al and DE 38 20 328 C2 teach rotor brakes which have tong or clamp-like arms arranged in mirror symmetry. The tong arms have an asbestos-free brake lining on their ends. When the brake is actuated, the brake linings are simultaneously placed on the rotor shaft and thus brake the spinning rotor from its high speed rotation during spinning operation to a standstill.
However, the known rotor brakes have the disadvantage that the service life of such brakes is relatively limited on account of the high stressing of the brake linings. That is, the frictional heat developing during the braking process causes the brake linings, which consist of a metal-containing, fiber-reinforced, asbestos-free and solvent-free material bound to artificial resin, to become glassy or vitreous over the course of time in the area where they contact the rotor shaft.
Such glassy brake linings adversely affect the functioning of the brake considerably since they result in distinctly longer braking times and therewith in a measurable loss of working efficiency of the entire open-end spinning machine. There is also the danger that the spinning-start carriage which services the open-end spinning machine may prematurely engage at a spinning location whose spinning rotor has not yet been completely braked. In this instance, both the service units of the spinning-start carriage as well as the open-end spinning device can experience considerable damage.